Device for stretching fabrics widthwise



July 14, 1931 Filed May 1 1950 2 Sh eets-Sheet 1 w u R H ||n 2 J. 0 a IO .O T r N f- OVfl O OO O OOO OO O O O OOW m a m i F A H 7 1 2 3 4 5 6 9\\\l b, w. 1 2 w w n I J E m a M v 2 w W M nw o o o o o owooo [\I Iwin.) IW FI 1 5 July 14, 1931. H. WEISS 1,814,652

DEVICE FOR STRETCHING FABRICS WIDTHWIS E Filed May 1, 1930 2Sheets-Sheet 2 O O O O O 0 4 O O 7/ O o 5' O I 5 [a I O 7, O A l 2 r O O9 o 0 O O 1m 1 l/vl ENTORx MM J/M'W,

Patented July 14, 1931 k UNITEDVSTATES PATENT OFFICE I HANS WEISS, orUZWIL, SWITZERLAND, essrenon TO! THE FIRM. M'ASCHINENFABRIK BENNINGEB A.G., or UZWIL, SWITZERLAND DEVICE roa STRETCHING FABR-Ics WIDTjI-IWISE-Application filed May 1, 1930, Serial No.

ing fabrics widthwise, of known type, comprising a series of curvedrollers which are driven by means of gear wheels. I

WVhen a shrunk web of fabric impregnated with sodium lye, for stretchingthe same widthwise, is passed over rollers of this type, at the end ofthe series of rollers very often an unequal lateral stretching effectand a de fiection of the weft threads results ,for the followin reason:In passing OVer the front rollers of the device for stretching thefabric widthW-ise the latter due to its elasticity and the small initialinternal stresses is-induced to positively follow the individualstretching roller elements and, consequently, it is uniformly stretchedall over its entire width. WVith increasing lateral stretching actionthe internal stresses of the fabric are increased and the moment thatthese stresses become greater than the adhesion of the fabric the latterbegins to slip in the axial direction. Experience shows that theaxialslippage is greatest at the edges of the fabric, whilst the centerthereof has no tendency to slip. Thus.

the edge portions aresubjectedto less lateral stretching than the centerportions of the web of fabric.

In-consequence of the adhesion ofthe Web of fabric being eliminated atthe edges thereof thefabric besides begins to slip in the directiontangentially of the rollers, thus lagging behind the circumference ofthe roller sothat the edges of the fabric are leading. on the centerportion'of the same, whereby the deflection ofthe weft threads iscaused.

When the said slippage occurs abruptly "0r irregularly, as the case maybe, anundulous edge line and a web 'of fabric of variable width willresult.

To overcome these drawbacks devices for stretching fabrics widthwisewere provided with rollers of different character, whereby eitherstraight and curved rollers were arranged in a row, or else groups ofrollers of 449,030, and in Germany May e, 1929.

different curvature were interconnected by conical transmission rollers.Both arrangements Were not satisfactory in respect of the lateralstretching'eifect and the Worst of all was that the wear of'the drivingmeans for the individual rollers was too great.

The object of the invention is to obviate these drawbacks inthat-according to the invention in a device for stretching fabricswidthwise the curvature of stretching rollers ofthe same character, thecurvature being continuous all over the length of the roller, isgradually decreased from the entrance to the delivery end of the device.

' Owing -to this arrangement the extent of the stretching effect in thefabric decreases corresponding to the increase of the lateral stressesin the fabric and thereby the latter is prevented from slipping on theperiphery of the rollers. Consequently, the total lateral stretchingeffect is improved by the slipping of theedge portions being'avoided andthe fabric is uniformlystretched along. its entire width, the weftthreads thus remaining straight- Furthermore, the formation of anundulousedge line i. e. a variation in the width of the fabric isprevented. Moreover,

, as the gaps between the roller elements decrease with the curvature ofthe rollers decreasing a detrimental overstretching of the .fabric[which is already considerably stretched is avoided.

Suitably the arangement is such that the rollers for thelateralstretching of the same character are combined into groups ofstretchingrollers of equal curvature and betweeneach pair of adjacentgroups a middle roller is arranged which averages in curvaturebetween the. curvatures of the adjacent rollers of the respectiveindividual groups and formswithsaid rollers a group of three rollers ofdecreasing curvature with regard to therun' of the fabric Web, whereby aslightly conical drivin'g gear wheel is, provided at each endjof saidmiddle roller. Y I

Alternatively, with an arrangement of a series of rollers with thecurvature of the latter gradually decreasing from roller to roller allrollers may be provided with slightly conical driving gear wheels.

In the accompanying drawings two constructional forms of the inventionare schematically illustrated, by way of example, only the partsnecessary for a good understanding of the invention being shown.

Fig; 1 shows a first constructional form the invention in plan view;

Fig. 2 is an elevation of Fig. 1;

Fig. 3 shows asecond constructional form of the invention in plan view;and

Fig. 4 an elevation of Fig. 3.

The device for stretching fabrics widthwise shown in Figs. 1 and 2comprises ten stretching rollers 1 to 10. The first six rollers 1 to 6from the entrance end of the device constitute a first group I and areall provided with the same relatively great continuous curvature whichmay be circular, parabolical or elliptical. The three last rollers 8, 9and are combined to a further group II of rollers of equal, butconsiderably smaller curvature than the rollers of the first group. Inelevation the axes of therollers are arranged in a zig-zag line, inknown manner (see Fig. 2). The transmission roller 7 between the groupsI and'II has a curvature which is equal to the mean value of thecurvatures of' the other rollers. All the-rollers 1 to 6 and 8 to 10 arefixed on the machine frame in known manner and operatively connectedwith each otherby meansof spur gear wheels 11, whilst the roller 7 isprovided with slightly conical. gear wheels 12. The spur gear wheels 11of rollerl as well as those of roller 9 eachmesh with a gear wheel 13-and 14 respectively having helical teeth, and being mounted in pairs ona common shaft 15 and 16 respectively, whereof the former is actuated byachain drive 17 and connected to the shaft 16' by a further chain drive18. The shafts 15. and 16 are mounted on the machine frame in knownmanner. All the rollers 1' to .10 are composed of individual roller elements 19 rotatably arranged on the shaft of' the roller in a mannerknown per se. The direction of movement of the web of fabric through thedevice is indicated by the ar rows A.

The described device permits a. greater number of stretching rollers tobe used in order to be enabled to obtain a thorough washing effect alonga travel of considerable length of the web of fabric with the latter instretched. condition without the quality of the fabric being impaired,such washing effeet being required for a com lete mercerization.Thereby, in contra ist'i'nction to known arrangements, a gradualtransition from the curvedl'entrance rollers to the straight deliveryroller is brought about and the possibility of the structure of the webbeing brought out of shape at the delivery end is greatly reduced. Therollers of smaller curvature are naturally subjected to less strain andwear which is very advantageous for instance in mercerizing machineswhere the last rollers are entirely or in part im- Inersed in the liquidbath and thus are diflicult to be lubricated.

In the constructional form, shown in Figs. 3 and 4, a series of rollers1 to 10 of the same character and of gradually decreased curva ture inrespect of the direction of movement of the fabric web, as indicated bythe arrows A, are arranged behind each other. The rollers areoperatively connected with each other by slightly conical spur gearwheels 11 at each end thereof and the drive is imparted to the whole.series at the roller 1 from the driving shaft 20, mounted on the machineframe in usual manner, by means of a pair of conical gear wheels 21 anda further conical wheel 22.

I claim:

1. In a device for stretching fabrics widthwise of the type described,in combination, a series of stretching rollers of the same character andof continuous curvature, said curvature of the rollers decreasing fromthe entrance end towards the delivery end of the device.

2. In a device for stretching fabrics widthwise of the type described,in combination, a plurality of individual groups of stretching rollers,all rollers being of the same character and of continuous curvature andeach group comprising rollers of equal curvature, a spur gear wheel ateach end of each roller of each group, a roller arranged between eachpair of adjacent individual groups, said middle roller averaging incurvature between the curvatures of the adjacent rollers of therespective individual groups and forming with said rollers a group ofthree rollers of decreasing curvature with regard to the run of thefabric web, and a slightly conical driving gear wheel at each end ofsaid middle roller.

3. In a device for stretching fabrics widthwise of the type described,in combination, a series of stretching rollers of the same character andof continuous curvature, said curvature of the rollers decreasing fromthe entrance end towards the delivery end of the device and each rollerprovided with slightly conical driving gear wheels.

In testimony whereof I have signed my name to this specification.

HANS WEISS.

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